The use of powdered metals and powdered ceramics for making products such as internal combustion engine components is well known and is growing due to the fact that the powders can be conveniently compressed into a shaped die with binders and other additives well known to those skilled in the art and which then are characteristically sintered in the case of powdered metal and sintered or nitrided and sintered in the case of powdered ceramics by processes well known in the art to produce virtually a finished product requiring minimal finish machining while greatly reducing machining scrap loss.
Such products however characteristically exhibit a certain degree of porosity in which the pores retain oil and oil-like materials used during their manufacture that are difficult and time consuming to remove.
The process of the present invention not only provides a rapid and effective way for removing oil and oil-like materials from porous parts such as powdered metal engine valves and powdered metal or powdered ceramic valves guides and valve seats but also can be tailored to provide a surface on the part that is essentially residue free which greatly enhances the ability to adhere another material to the surface by bonding or welding and the like in the event such is required.
The process of the present invention employs, in part, alkaline soap and water solutions and (when tailored to provide an essentially residue-free surface) predetermined mixtures of deionized water and water soluble amines such as morpholine disclosed in my co-pending application Ser. No. 239,255, titled "Metal Cleaning Process" in which it is disclosed that the use of aqueous amine solutions, such as morpholine and ordinary water solutions, for passivating steel is taught in U.S. Pat. No. 4,590,100 and the use of morpholine for rectifying chlorinated hydrocarbon deposits on copper is disclosed in U.S. Pat. No. 4,080,393, the disclosures of both of which are included herein by reference.